Hydraulic conductivity is the ability of a porous media to transfer water through its pore matrix. That is a key parameter for the design and analysis of soil fluid associated structures and issues. This paper present...Hydraulic conductivity is the ability of a porous media to transfer water through its pore matrix. That is a key parameter for the design and analysis of soil fluid associated structures and issues. This paper presents the test results of the vertical hydraulic conductivity k<sub>v</sub><sub> </sub>carried out on one poorly graded sand and three gap graded gravely sand. It was found that the vertical hydraulic conductivity of saturated soil depends on the grain size distribution curve, on the initial relative density of the soil. Compilation of these current test results and other test results published, shows that the common approaches predict well to some extent the vertical hydraulic conductivity k<sub>v</sub> for the poorly graded sand materials and underestimate the k<sub>v</sub> values for gap graded gravely sand materials. Therefore, new approaches are developed for the prediction of the vertical hydraulic conductivity in saturated poorly graded sand and gap graded gravely sand. The derived results from the new approaches lie in the range of the recommended values by (EAU 2012) and (NAVFAC DM 7 1974).展开更多
Biodiversity and tropical forests play a fundamental role in the life of the black people of Africa. In Benin, while some aspects of this role are well-documented, others are barely known. Moreover, these information ...Biodiversity and tropical forests play a fundamental role in the life of the black people of Africa. In Benin, while some aspects of this role are well-documented, others are barely known. Moreover, these information remains so far very scattered through the literature which does not allow to have a global view on the contribution of biodiversity and forests to the life of people. In this work, it is presented the role of forests and biological diversity in the main vital areas of life of populations in south of Benin. The methodology used was based, with regard to the field, on bibliographical research, observation and/or field stakeholder survey. Investigations are more particularly focused on hardwood lumber uses and the species that are significantly used. The results highlight the uses that are made of vegetal elements of biological diversity and timber as forest products in south of Benin. The main areas explored are animist or traditional religion and traditional medicine, as well as socio-cultural and economic life. In this latter area, the most used timber species and their uses are identified; these include furniture, light carpentry, sculpture, formwork, canoe construction, drums and mortar making.展开更多
文摘Hydraulic conductivity is the ability of a porous media to transfer water through its pore matrix. That is a key parameter for the design and analysis of soil fluid associated structures and issues. This paper presents the test results of the vertical hydraulic conductivity k<sub>v</sub><sub> </sub>carried out on one poorly graded sand and three gap graded gravely sand. It was found that the vertical hydraulic conductivity of saturated soil depends on the grain size distribution curve, on the initial relative density of the soil. Compilation of these current test results and other test results published, shows that the common approaches predict well to some extent the vertical hydraulic conductivity k<sub>v</sub> for the poorly graded sand materials and underestimate the k<sub>v</sub> values for gap graded gravely sand materials. Therefore, new approaches are developed for the prediction of the vertical hydraulic conductivity in saturated poorly graded sand and gap graded gravely sand. The derived results from the new approaches lie in the range of the recommended values by (EAU 2012) and (NAVFAC DM 7 1974).
文摘Biodiversity and tropical forests play a fundamental role in the life of the black people of Africa. In Benin, while some aspects of this role are well-documented, others are barely known. Moreover, these information remains so far very scattered through the literature which does not allow to have a global view on the contribution of biodiversity and forests to the life of people. In this work, it is presented the role of forests and biological diversity in the main vital areas of life of populations in south of Benin. The methodology used was based, with regard to the field, on bibliographical research, observation and/or field stakeholder survey. Investigations are more particularly focused on hardwood lumber uses and the species that are significantly used. The results highlight the uses that are made of vegetal elements of biological diversity and timber as forest products in south of Benin. The main areas explored are animist or traditional religion and traditional medicine, as well as socio-cultural and economic life. In this latter area, the most used timber species and their uses are identified; these include furniture, light carpentry, sculpture, formwork, canoe construction, drums and mortar making.
